10 things you might now know about space

Russia's Phobos-Grunt spacecraft, a Mars probe that malfunctioned, is expected to fall back into Earth's atmosphere as early as this weekend. It will crash to our planet's surface, but is unlikely to hurt anyone on the ground. These 10 facts won't hurt either:

1 Where does Earth's atmosphere end and outer space begin? NASA defines an astronaut as someone who has flown 50 miles above sea level. But some international groups prefer to define space as the area beyond the Karman Line, which is about 62 miles above sea level.

2 Living in space can cause subtle changes in the human body. For example, some astronauts find that their tastes in food change. "One of my favorite foods on the ground is shrimp, and up here I can't stand it," said International Space Station astronaut Peggy Whitson.

3 Speaking of food and space, South Korean researchers spent more than $1 million on kimchi that astronaut Yi So-yeon took to the International Space Station in 2008. Scientists had to develop a special version of the pickled cabbage dish to address fears that it would offend crew members from other countries with its smell or that it would start "bubbling out of control" in space conditions.

4 Neil Armstrong misspoke when he uttered the first words on the moon in 1969. He was supposed to announce, "That's one small step for a man, one giant leap for mankind." But he left out the "a," producing a sentence that didn't really make sense. (Without the "a," "man" would mean the same thing as "mankind.") But, of course, everyone knew what he meant.

5 Sitting in the Centaurus constellation about 20 light years from Earth is star BPM 37093, also named Lucy. The white dwarf is one huge diamond, scientists say, that weighs in at 10 billion trillion trillion carats and is about the size of our moon.

6 In 1993, a meteoroid destroyed the European Space Agency's communication satellite Olympus. Don't think Hollywood explosion. Scientists suspect it was damaged by a few pebbles, and in trying to regain control, so much fuel was lost the satellite was rendered useless. While space shuttles, space stations and satellites have received minor damage from flying space rocks, the Olympus is the only satellite to be rendered useless.

7 Before "The Big Bang Theory" was a TV show, it was an explanation for the development of the universe, and much of the credit (for the theory, not the TV show) goes to a former Chicagoan. Edwin Hubble set the Illinois high jump record while at Wheaton High School, won a Rhodes scholarship, and earned a doctorate at the University of Chicago. But the ultimate honor — the Nobel Prize — eluded him because some Nobel officials didn't think astronomy fit into the physics category.

8 The word "jovial" comes from Jove, another name for the god (and the planet) Jupiter. The god was considered jolly, so those who are similarly good-natured are jovial. But in space terms, a "jovian planet" is not at all jolly — it's a planet that, like Jupiter, is composed primarily of gases rather than solid matter.

9 When you point out the Big Dipper to your child, be careful not to call it a constellation. It's an asterism, or a collection of stars within a constellation or in multiple constellations that form another shape. Another famous asterism is Orion's Belt. There are 88 official constellations, including Orion, Gemini, the zodiac signs and Ursa Major, which includes the Big Dipper.

10 The ashes of more than 100 humans have been launched into space, including those of "Star Trek" creator Gene Roddenberry and hippie icon Timothy Leary. But the first human ashes to leave the solar system are expected to be those of Clyde Tombaugh. The remains of the astronomer who discovered Pluto are aboard the New Horizons spacecraft, scheduled to fly past Pluto in 2015 and take photographs, then depart our solar system.

Mark Jacob is a deputy metro editor at the Tribune; Stephan Benzkofer is the Tribune's weekend editor.